Encoded PDF string droped from DataTable upon inserting a DataRow

I am receiving a payload from a web service where i get a pdf file encoded in base64. The web service returns the pdf in a really large string that I store in a DataRow first:

DataRow info = ServiceInfo.NewRow();
info["ServiceName"] = serviceName;
info["Response"] = Jobj.SelectToken("response");
info["Message"] = Jobj.SelectToken("message");
info["Payload"] = Jobj.SelectToken("payload");

So in the info["Payload"] i get the results correctly

Full string file can be found at this location

ServiceInfo.Rows.Add(info);

The moment I add it to the DataTable ServiceInfo the payload is lost, and it shows as empty

Does anybody have any advice on my problem?

Thanks :D